Posted
by
Soulskill
on Wednesday December 18, 2013 @06:47PM
from the ready-to-stake-my-claim dept.

astroengine writes "Astronomers scoping-out the vicinity of the famous star Fomalhaut have discovered that its mysterious stellar sister is also sporting a rather attractive ring of comets. Located 25 light-years away in the constellation Piscis Austrinus, Fomalhaut A is one of the brightest stars in Southern Hemisphere skies. The bright blue giant is notable in that it hosts a gigantic ring of cometary debris and dust. Fomalhaut C is a red dwarf star and was only confirmed to be gravitationally bound Fomalhaut A and Fomalhaut B in October. Fomalhaut is therefore a triple, or trinary, star system. The small red dwarf star may be the proverbial runt of the Fomalhaut stellar litter, but it appears to share some common ground with its larger sibling. 'It's very rare to find two comet belts in one system, and with the two stars 2.5 light years apart this is one of the most widely separated star systems we know of,' said astronomer Grant Kennedy, of the University of Cambridge and lead researcher of this work. 'It made us wonder why both Fomalhaut A and C have comet belts, and whether the belts are related in some way.' One of the reasons why Fomalhaut A's cometary disk is so bright is down to the presence of its exoplanet, stirring up comet collisions. Fomalhaut C may be experiencing the same mechanism."

Also written about by damned near every sci-fi writer there ever was. I'm wondering what someone who has never heard of it is doing at slashdot? Since he's AC he's probably a jocktroll. The lack of capitalization suggests he's a young jocktroll who wishes he was smart enough to be a nerd.

To say another star has an exoplanet seems redundant. Why not just say it has planets?

In fact, seems to me that all stars have exoplanets, by definition.

Exi-planets would probably mean something like, they are being absorbed into the star.

Exo-planets is the sort of thing we live on. Scienterrific types like terminology, it's what they write White Papers with rather than "Y'know, there's like a bunch of stuff out there", which is meaningful, but isn't going to get you anywhere in a scientific body.

Planets orbit Sol. An exoplanet is a planet that orbits any star that is not named Sol. Maybe it's useful to say 'we've discovered X number of exoplanets' at this point of discovery, but I imagine it will get dropped eventually. Scientist don't usually stick with anthropocentric terminology.

To say another star has an exoplanet seems redundant. Why not just say it has planets?

For practically all practical purposes, everybody who uses both words "planet" and "exoplanet" in practice, the difference matters. Language is a tool, and it is practical to have words which are a compromise which between avoiding ambiguity, being short, being consistent, and being practical.

For example, now and at least several decades into future, you can resolve the disk of "planets" with telescopes, and even see most of them with Eyeball Mk1. Contrast this to "exoplanets", at best for a few cases you c

As the summary notes, it was only recently discovered that this system has three gravitationally bound stars, making it the widest such group currently known. Paper from a few months ago [arxiv.org] on the arXiv, and a news write-up [phys.org] of that.

The cool part: ""Fomalhaut C looks quite far apart from the big, bright star that is Fomalhaut A when you look up at the sky from Earth," added Mamajek. There are roughly 5.5 degrees between the two stars, which is as if they were separated by roughly 11 full moons for an observer on Earth. Mamajek explained that they look this far apart, in part, because Fomalhaut is relatively close to Earth as stars go – approximately 25 light years."